The present inventive concept relates to integrated circuit devices, and, in particular, to integrated circuit memory devices.
Memory density has been constantly increasing to keep up with the rapid developments and ever-increasing demands of modern digital technology. In particular, as electronic devices become smaller and smaller, it may be important to provide higher memory densities in such compact devices.
As the prices of non-volatile memory have decreased in recent years, solid state drives (SSDs) have been increasingly used in computer systems and portable devices. SSDs may use non-volatile memory to store data, and may offer several advantages (such as increased speed) over hard disk drives. FIGS. 1A and 1B illustrate the layout of a typical SSD 100. In particular, FIG. 1A illustrates a first side of the SSD 100, while FIG. 1B illustrates a second side of the SSD 100. As shown in FIGS. 1A and 1B, the printed circuit board (PCB) 110 in a SSD may include a buffer memory 122, an interface 124, and plurality of multi-chip memory packages (MCPs) 105. The MCPs 105 are electrically connected to a memory controller 120. The memory controller 120 is configured to control 2″ chips, where n is the number of address bits. As such, each of the packages 105 includes 2″ chips. The memory density of the SSD may be doubled with each additional address bit.
While current mass production technologies and fabrication methods are continuously developing, a typical MCP may include 8-chip or 16-chip stacks. For example, as shown in FIGS. 1A and 1B, each of the MCPs 105 includes 8 chips, and the PCB 110 is configured to hold 16 of the MCPs 105. However, due to various problems, such as low yields, it may be difficult to stack more than about 16 chips in a package using current mass production techniques.